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Kato, Atsushi; Kubo, Shigenobu; Chikazawa, Yoshitaka; Miyagawa, Takayuki*; Uchita, Masato*; Suzuno, Tetsuji*; Endo, Junji*; Kubo, Koji*; Murakami, Hisatomo*; Uzawa, Masayuki*; et al.
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Sustainable Clean Energy for the Future (FR22) (Internet), 11 Pages, 2022/04
The authors are carrying out conceptual design studies for a pool-type sodium-cooled fast reactor. There are main challenges such as measures against severe earthquake in Japan, thermal hydraulic in a reactor vessel (RV), a decay heat removal system design. When the JP-pool SFR of 650 MWe is installed in Japan, it shall be designed against the severe seismic conditions. Additionally, a newly three-dimensional seismic isolation system is under development.
Nibe, Nobuaki; Shimakawa, Yoshio; ; Hayafune, Hiroki; ; ;
JNC TN9400 2000-074, 388 Pages, 2000/06
JNC-TN9400-2000-074.pdf:13.32MB
Large sized sodium-cooled fast breeder reactors of large-size are being studied and have been operated in Japan and many countries. ln this feasibility study, evaluation was made on technical feasibinty for design concepts or 1 loop type and 3 pool types, specially from the viewpoint of improvement of economical competence. The design concepts include the ideas of cost reduction measures such as large-scaled components, reduction of loop number and integration of components on the basic of utilization of sodium characteristics. From the results of the evaluation, it may be possible for all the concepts to attain the economical target of 200 thousands yen per kilowatt, though further confirmation should be made for technical feasibility of those concepts. ln addition, the following items were listed up as further cost-reduction measures. (1)Higher temperature cooling system and steam cycle efficiency (2)Shortening of construction term (3)Reduction of safety systems by using measuring instruments with high performmce (4)Adoption of SG-ACS
Hagiwara, Hiroyuki*; Watanabe, Osamu*; Oyama, Kazuhiro*; Ando, Masato*; Ohshima, Hiroyuki; Yamano, Hidemasa
no journal, ,
Thermal hydraulic evaluation has been carried out for a pool-type sodium-cooled fast reactor to identify thermal hydraulic issues inside the reactor vessel which would be important in introducing the pool reactor. This study identified temperature change in the outer surface of the inner vessel in a reactor trip, natural convection of the reactor vessel wall cooling part in a full power operation, and cover-gas entrainment of the hot-pool free surface as important thermal hydraulic issues to be investigated in future.
Chikazawa, Yoshitaka; Kubo, Shigenobu; Miyagawa, Takayuki*; Eto, Masao*
no journal, ,
Thermal transient on reactor vessel around sodium surface in a pool type reactor has been evaluated. Taking into account severe earthquake conditions, thickness of the reactor vessel is increased from the original design. Thermal transient evaluation including creep fatigue and ratchet at the sodium surface have been evaluated on that improved reactor vessel design against seismic load.
Uchita, Masato*; Dozaki, Koji*; Suzuno, Tetsuji*; Fukasawa, Tsuyoshi*; Hayafune, Hiroki; Kato, Atsushi
no journal, ,
Seismic evaluation on the reactor vessel of the pool type sodium-cooled reactor has been conducted using seismic conditions for domestic LWR sites. And parametric design survey when the reactor output is enlarged has also conducted showing available reactor vessel thickness with holizontal seismic isolation system and advanced design with three-dimensional seismic isolation system.
Matsushita, Kentaro; Ito, Kei*; Ezure, Toshiki; Tanaka, Masaaki
no journal, ,
A numerical simulation code named SYRENA has been developed in JAEA to analyze the behavior of entrained bubbles and dissolved gas in the primary coolant of sodium-cooled fast reactor (SFR). In the present study, a flow network model for a pool-type SFR was newly developed in SYRENA and the non-condensable gas behavior in the pool type SFR was analyzed. A dipped-plate (D/P) model was introduced into the flow network to investigate influences of D/P installation on the non-condensable behavior in the pool-type reactor. A parametric study was performed on the exchange flow rate through the D/P and the gas entrainment rate at the free surface existing above the D/P. The non-condensable gas behavior under various flow conditions, e.g. gas entrainment rate condition, was obtained. Especially, it was observed that the bubble volume in the primary coolant system changed with the exchange flow rate though the change ratio is dependent on the gas entrainment.
Nakamura, Hironori*; Uchita, Masato*; Hayakawa, Satoshi*; Matoba, Ichiyo*; Watanabe, Osamu*; Onoda, Yuichi; Tanaka, Masaaki
no journal, ,
no abstracts in English
Takano, Kazuya; Kato, Atsushi; Uchita, Masato*; Murakami, Hisatomo*
no journal, ,
Control rods of pool-type SFR are not fixed radially in the control rod guide tubes. Relative offset between control rods and around in-vessel structures occurs in an earthquake situation. The relative offset could lead three-point restraint of the control rods and difficulty of their insertion. In the present study, the seismic offset was quantitively evaluated and was compared with the criteria of the three-point restraint in the current design of pool-type SFR with 600 MWe. As the evaluated offset is below the criteria, the three-point restraint in an earthquake can be prevented in the current design of pool-type SFR. In addition, several measures were examined to increase the margin of control rods insertability.
Kato, Atsushi; Onoda, Yuichi; Miyagawa, Takayuki*; Endo, Junji*; Kubo, Koji*
no journal, ,
JAEA is studying 600 MWe pool-type sodium-cooled fast reactor. This report presents thermal hydraulic study in a reactor vessel and structural intactness evaluation in case of station black out and reactor trip.
Takano, Kazuya; Kato, Atsushi; Uchita, Masato*; Okazaki, Hitoshi*; Ikari, Risako*
no journal, ,
Primary Heat Transport System (PHTS) flow rate is the most promising signal to detect the pump/diagrid link rupture in pool type SFR. The electromagnetic flowmeter is considered to measure the PHTS flow rate and is designed to install nearby outlet of the PHTS circulation pump in the current design of pool-type SFR with 600 MWe. The flowmeter could be significantly affected by the noise from pump motor. In order to improve the signal strength, the structure of flowmeter is drastically modified with the D-shape yokes and the magnetic circuits above and below an electrode.
Hara, Hiroyuki*; Tamura, Shogo*; Yamamoto, Tomohiko
no journal, ,
no abstracts in English
Eto, Masao*; Yokoi, Shinobu*; Yamashita, Masato*; Miura, Kazuhiro*; Okafuji, Takashi*; Onoda, Yuichi; Yamamoto, Tomohiko; Uchita, Masato*
no journal, ,
no abstracts in English